Influence of the vacuum interface on the charge distribution in V2O3 thin films

TL;DR

This study uses density functional theory to analyze how vacuum interfaces affect charge distribution in V2O3 thin films, revealing that charge redistribution is confined to a very thin surface layer and does not explain the films' thickness-dependent metal-insulator transition.

Contribution

It demonstrates that vacuum interface effects on charge redistribution are limited to a narrow surface layer in V2O3 thin films, ruling out charge redistribution as the cause of the thickness-dependent transition.

Findings

Charge redistribution is confined to ~15 Å surface layer.

Vacuum interface effects do not account for the thickness dependence.

Charge redistribution is not responsible for the metal-insulator transition variation.

Abstract

The electronic structure of V2O3 thin films is studied by means of the augmented spherical wave method as based on density functional theory and the local density approximation. We establish that effects of charge redistribution, induced by the vacuum interface, in such films are restricted to a very narrow surface layer of approx. 15 Angstroem thickness. As a consequence, charge redistribution can be ruled out as a source of the extraordinary thickness-dependence of the metal-insulator transition observed in V2O3 thin films of 100-1000 Angstroem thickness.